1. Field of the Invention
This invention relates to fluid flow meters and more particularly to fluid flow meters having impulse generators for actuating readouts located remotely from the fluid flow meter.
2. Description of the Prior Art
In conventional water flow meters, the register forms a part of the measuring mechanism rendering the register inconvenient to read because the mechanism is generally located in the basement of a home or other building. Prior art meters have been developed which include a remote register electrically interconnected to the meter and mounted in a more convenient location, for example on the exterior of the building in which the meter is contained. Typically, these meters include impulse generators which produce an electric signal whenever a fixed volume of fluid passes through the meter. Typically, the generators are driven by biased spur gears, which are released in response to a fixed volume of flow to drive the generator. The remote registers are actuated by the generator signals to provide a readable display.
Prior impulse generators used in fluid flow meters are inadequate for several reasons. One drawback is the relatively high cost of construction of separate magnet field and coil components and the subsequent assembly of such components. For example, the impulse generator shown in U.S. Pat. No. 3,772,917, issued Nov. 20, 1973 to Lutz and Booth, includes a number of intricate components such as ring magnets, a shield, a steel core, wiring, and other accessories such as pigtails. Consequently, the manufacture and assembly of these intricate and complex components is relatively expansive.
Further, many prior art impulse generators typically require a relatively high torque drive in order to generate an adequate, electric signal and they are less efficient, all because they only include a single, electric coil. This high torque requirement mandates that the generator drive gear be driven by a relatively large biasing force, which causes excessive stress and wear on the driving mechanism. Examples of single coil construction are shown in U.S. Pat. No. 3,772,917 and U.S. Pat. No. 3,685,353, issued Aug. 22, 1972 to Gesler, Kovats, and Kolakowski.
One prior fluid flow meter with a remote readout generates its remote-register, actuation signal by providing a plurality of stationary poles and a rotating magnet which combinaton generates an AC signal which is rectified to produce a DC pulse. Such a construction is shown in U.S. Pat. No. 3,599,022, issued Aug. 10, 1971 to Adair. This construction requires driving a relatively heavy magnet and is relatively complicated.
Generally, prior fluid flow meters with impulse generators are difficult to construct. The impulse generator is typically an "add-on" feature extending laterally of the normal meter housing as shown in U.S. Pat. No. 3,772,917. Alternatively, the impulse generators have been located above the meter register located on the metering device making reading of this register difficult as in U.S. Pat. Nos. 3,685,353 and 3,599,022. Prior constructions do not provide for modularity but instead require all components included in the meter to be carefully held in position until completion of the entire assembly.